This study aims to investigate the influence of multiple cyclic phase transitions on the micro-structure and low-temperature mechanical properties of 18Ni(250) ultra-high-strength steel to meet the stringent requirements of low-temperature wind tunnel tests.
Methods
2
An ultra-pure melting simulation model for vacuum induction and vacuum consumable smelting was constructed using MeltFlow software. The formation mechanism of the micro-structure inside the molten pool was analyzed and discussed. Based on the derived optimal parameters
the test steel was obtained through ultra-high-purity smelting. Subsequently
the steel was subjected to multiple cyclic phase transitions at 940 ℃
900 ℃
860 ℃ and 820 ℃
followed by conventional aging treatment.
Results
2
The results demonstrate that using a flow rate lower than 4.6 kg/min leads to an ingot with low segregation and low inclusions
which significantly improves the plastic toughness of 18Ni(250) steel. After undergoing the specific cyclic phase transitions
the original austenite grain size is notably refined to 12 μm. Consequently
the steel exhibits excellent mechanical properties under low-temperature and high-load conditions
characterized by the successful combination of ultra-high strength and high plasticity.
WU Jifei , KONG Wenjie , LI Guoshuai , et al . Progress and prospect on Reynolds number effects of advanced aircraft [J]. Acta Aerodynamica Sinica , 2024 , 42 ( 8 ): 35 - 59 . (In Chinese)
YANG Z S , PENG F L , QIAO Y K , et al . A new cryogenic sealing process for the launch and reception of a tunnel shield [J]. Tunnelling and Underground Space Technology , 2019 , 85 : 406 - 417 .
REN Yanru , LIU Zhouli , YANG Weiyu , et al . Effect of solution temperature on impact property of new Co-free maraging steel 00Ni14Cr3Mo3Ti [J]. Special Steel , 2020 , 41 ( 1 ): 64 - 67 . (In Chinese)
HUANG G , WEI K W , DENG J F , et al . High power laser powder bed fusion of 18Ni300 maraging steel:processing optimization,microstructure and mechanical properties [J]. Materials Science and Engineering:A , 2022 , 856 : 143983 .
RAO M N . Progress in understanding the metallurgy of 18% nickel maraging steels [J]. International Journal of Materials Research , 2022 , 97 ( 11 ): 1594 - 1607 .
GUO L L , ZHANG L N , ANDERSSON J , et al . Additive manufacturing of 18% nickel maraging steels:defect,structure and mechanical properties:a review [J]. Journal of Materials Science & Technology , 2022 , 120 : 227 - 252 .
ZHENG Buyun , CHEN Xin , LEI Jianbo , et al . Effect of heat treatment on microstructure and mechanical properties of 18Ni300 maraging steel prepared by laser melting deposition [J]. Surface Technology , 2023 , 52 ( 3 ): 388 - 398 . (In Chinese)
ROHIT B , MUKTINUTALAPATI N R . Austenite reversion in 18% Ni maraging steel and its weldments [J]. Materials Science and Technology , 2018 , 34 ( 3 ): 253 - 260 .
DAI Yujie , WANG Kui . Study on the isothermal quenching process of C55E steel chain plates with JMatPro software [J]. Journal of Mechanical Transmission , 2024 , 48 ( 6 ): 147 - 152 . (In Chinese)
YIN S , CHEN C Y , YAN X C , et al . The influence of aging temperature and aging time on the mechanical and tribological properties of selective laser melted maraging 18Ni-300 steel [J]. Additive Manufacturing , 2018 , 22 : 592 - 600 .
SANATKUMAR B S , NAYAK J , NITYANANDA SHETTY A . Influence of 2-(4-chlorophenyl)-2-oxoethyl benzoate on the hydr-ogen evolution and corrosion inhibition of 18 Ni 250 grade weld aged maraging steel in 1.0 M sulfuric acid medium [J]. International Journal of Hydrogen Energy , 2012 , 37 ( 11 ): 9431 - 9442 .
SONG J , TANG Q , FENG Q X , et al . Effect of heat treatment on microstructure and mechanical behaviours of 18Ni-300 maraging steel manufactured by selective laser melting [J]. Optics & Laser Technology , 2019 , 120 : 105725 .
TAN Chaolin , ZHOU Kesong , MA Wenyou , et al . Research progress of laser additive manufacturing of maraging steels [J]. Acta Metallurgica Sinica , 2020 , 56 ( 1 ): 36 - 52 . (In Chinese)
ZHANG J , FAN J K , XU J Q , et al . The effect of heat input on the microstructure and mechanical properties of 18Ni 300 maraging steel fabricated by arc directed energy deposition [J]. Materials Science and Engineering:A , 2023 , 884 : 145545 .
YAO Y , ZHU H T , HUANG C Z , et al . Determination of the minimum chip thickness and the effect of the plowing depth on the residual stress field in micro-cutting of 18 Ni maraging steel [J]. The International Journal of Advanced Manufacturing Technology , 2020 , 106 ( 1 ): 345 - 355 .
YANG Dongqing , WANG Xiaowei , HUANG Yong , et al . Microstructure and mechanical properties of 18 Ni maraging steel deposited by gas metal arc additive manufacturing [J]. Transactions of the China Welding Institution , 2020 , 41 ( 8 ): 6 - 9 . (In Chinese)
ZHU T , LI J , SAMANTA A , et al . Temperature and strain-rate dependence of surface dislocation nucleation [J]. Physical Review Letters , 2008 , 100 ( 2 ): 025502 .